- Tank leaching
Tank leaching, also called vat leaching, is a hydrometallurgical method of extracting valuable material (usually metals) from ore. It involves placing ore, usually after size reduction and classification, in large tanks or vats containing a leaching solution. Often the vats are equipped with agitators to keep the solids in suspension in the vats and improve the solid to liquid contact. This is further assisted by the use of tank baffles to increase the efficiency of agitation and prevent centrifuging of slurries in circular tanks. Aside from chemical requirements two key factors influencing extraction are retention time and shear within the leach tanks. Retention time refers to the total volumetric capacity of the leach tank/s divided by the volumetric throughput of the solid/liquid slurry. Retention time is commonly measured in hours for precious metals recovery. A sequence of leach tanks is referred to as a leach "train", and retention time is measured considering the total volume of the leach train. Broadly speaking shear refers to energy transfer into the slurry from power input e.g.agitation. The degree of energy input in conjunction with the tank configuration determines kinetics affecting solid liquid contact. After vat leaching, the leached solids and pregnant solution are usually separated prior to further processing.
The method is commonly used to extract
goldand silverfrom ore.
* [http://wiki.biomine.skelleftea.se/wiki/index.php/Tank_leaching Tank leaching, BioMineWiki]
Wikimedia Foundation. 2010.
Look at other dictionaries:
Leaching (metallurgy) — Leaching is a widely used extractive metallurgy technique which converts metals into soluble salts in aqueous media. Compared to pyrometallurgical operations, leaching is easier to perform and much less harmful, because no gaseous pollution… … Wikipedia
Leaching — In general, leaching is the extraction of certain materials from a carrier into a liquid (usually, but not always a solvent). Specifically, it may refer to:*Leaching (agriculture) *Leaching (chemical science) *Leaching (metallurgy) **Dump… … Wikipedia
Rainwater tank — A rainwater tank (sometimes called rain barrels , in North America or a water butt in the UK) is a water tank which is used to collect and store rain water runoff, typically from rooftops via rain gutters. Rainwater tanks are devices for… … Wikipedia
metallurgy — metallurgic, metallurgical, adj. metallurgically, adv. metallurgist /met l err jist/ or, esp. Brit., /meuh tal euhr jist/, n. /met l err jee/ or, esp. Brit., /meuh tal euhr jee/, n. 1. the technique or science of working or heating metals so as… … Universalium
конкретный источник загрязнения — — [http://www.eionet.europa.eu/gemet/alphabetic?langcode=en] EN point source Pollution from a discrete source, such as a septic tank, a sewer, a discharge type, a landfill, a factory or waste water treatment works discharging to a… … Справочник технического переводчика
environmental works — ▪ civil engineering Introduction infrastructure that provides cities and towns with water supply, waste disposal, and pollution control services. They include extensive networks of reservoirs, pipelines, treatment systems, pumping stations … Universalium
Trickling filter — A trickling filter consists of a fixed bed of rocks, gravel, slag, polyurethane foam, sphagnum peat moss, or plastic media over which sewage or other wastewater flows downward and causes a layer or film of microbial slime to grow, covering the… … Wikipedia
industrial glass — Introduction solid material that is normally lustrous and transparent in appearance and that shows great durability under exposure to the natural elements. These three properties lustre, transparency, and durability make glass a favoured… … Universalium
Mound system — A mound system is an alternative to the traditional rural septic system leach field. The mound system is an engineered leaching field used in areas where septic systems are more prone to failure due to having extremely slow or extremely fast… … Wikipedia
Glossary of environmental science — This is a glossary of environmental science.Environmental science is the study of interactions among physical, chemical, and biological components of the environment. Environmental science provides an integrated, quantitative, and… … Wikipedia